JP2010046384A - Medical manipulator and experimental device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical manipulator which can determine simply and properly the tensile strength of a flexible material. <P>SOLUTION: The medical manipulator 10 includes: an actuator block 30 equipped with motors 40a-40c; a connection part 15 equipped with pulleys 50a-50c which can be connected to the actuator block 30 to be detachably communicated with the motors 40a-40c; a tip operator 12 mounted to the tip of a coupling shaft 48 stretching from the connection part 15 to operate together with the pulleys 50a-50c via wires 54a-54c; and a tensile strength detection piece 400 interposed halfway of the wires 54a-54c, provided with a strain gauge 404a, wherein the tensile strength detection piece 400 is a board which is long along the stretching direction of the coupling shaft 48 and has hooks 406 at both the ends in the longitudinal direction to load the wires 54a-54c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a medical manipulator that drives a distal end working unit provided at the distal end of a connecting shaft via a flexible member by driving a motor from a control unit, and an experimental apparatus for developing the medical manipulator About.

  In endoscopic surgery (also called laparoscopic surgery), a plurality of holes are made in a patient's abdomen, etc., and a trocar (tubular instrument) is inserted as a passing port of the instrument, and then a shaft is provided. The distal end of the forceps is inserted into a body cavity through a trocar and the affected area is operated. A gripper, a scissors, an electric scalpel blade, and the like are attached to the distal end of the forceps as a working unit for gripping a living tissue.

  Endoscopic surgery using forceps requires a certain amount of training because the inside of the body cavity, which is the working space, is narrow and the forceps are operated using the trocar as a fulcrum. In addition, since the forceps used in the related art do not have a joint at the distal end working portion, the degree of freedom is small, and the distal end working portion can only operate on the extension line of the shaft. Therefore, there are limits to the cases that can be performed by normal training, and a considerably high level of training and proficiency is required to apply to various other cases.

  From such a viewpoint, a conventional forceps has been improved and a forceps having a plurality of joints in a working unit has been developed (for example, see Patent Document 1). The manipulator described in Patent Document 1 includes an operation unit that is operated manually and a work unit that is detachably attached to the operation unit. In such a manipulator, there are no restrictions or inconveniences like conventional forceps, the procedure is easy, the number of applicable cases increases, and various types of procedures can be handled by exchanging the types of working parts. Can do.

  On the other hand, a medical robot system that drives such a manipulator with a robot arm has been proposed (see, for example, Patent Document 2).

JP 2004-105451 A US Pat. No. 6,331,181

  As described above, the working unit in the medical manipulator may be configured to be replaceable with respect to the operation unit. This makes it possible to wear various types according to the procedure, clean only the working part after the procedure is completed, and replace only the working part with a new one periodically. Sufficient reliability can be ensured. That is, it is desirable that the operation unit is provided with many electrical components and is relatively expensive and can be used for as long as possible. However, the operation unit is inexpensive because there are no weak electrical components, and the operation unit Therefore, it is desirable to replace the tip operation unit with a new one at an appropriate time in consideration of mechanical life and damage caused by cleaning with steam and heat. As described above, it is assumed that the working unit is periodically replaced with a new one, and it is only necessary to have an appropriate life, and it is not necessary to have an excessively high strength.

  On the other hand, the working part has a connecting part connected to the actuator part and a connecting shaft extending from the connecting part, and the tip operating part is provided at the tip of the connecting shaft and is wound around the pulley of the connecting part. Interlocks with a flexible member such as a plurality of wires. These flexible members repeat the arc state wound around the pulley according to the reciprocating motion and the linear state apart from the pulley, and are repeatedly subjected to bending stress. In particular, the lifetime is relatively short, and the influence of the lifetime due to tension is particularly great.

  Therefore, it is preferable to consider the tension of these flexible members in determining or managing the life of the working unit. Moreover, it is desirable that the tension of the wire is inspected not only at the product level but also at the product development stage in accordance with the operating condition.

  The present invention has been made in view of such a problem, and develops a medical manipulator that can easily and appropriately detect the tension of a flexible member in a detachable working portion, and the medical manipulator. An object of the present invention is to provide an experimental apparatus.

  A medical manipulator according to the present invention includes an actuator unit including a motor, a connection unit that is detachably attached to the actuator unit and connected to a rotation shaft of the motor, and a connecting shaft extending from the connection unit. A distal end working part that is linked to the rotating body via a flexible member, and a tension detection piece that is interposed in the middle of the flexible member and is provided with a strain sensor. Features.

  By providing such a tension detection piece, the tension of the flexible member in the working part can be detected easily and appropriately.

  The tension detecting piece may be a plate that is long in the extending direction of the connecting shaft. Such a plate does not hinder the operation of the flexible member, and has an appropriate rigidity, is easily provided with a strain sensor, and can accurately detect the tension.

  The strain sensors may be provided on the front and back sides of the tension detection piece. Thereby, it is possible to reduce the influence of tension detection caused by bending of the tension detection piece.

  The tension detection piece can be easily attached by providing hooks for hooking the flexible member at both ends in the longitudinal direction.

  If the tension detection piece is a nickel-base alloy, stainless steel, or hardened steel, it has sufficient strength and is suitable for tension detection.

  The flexible member is wound around a distal end rotating body of the distal end working unit, and two reciprocating lines are provided substantially in parallel in the connecting shaft, and the tension detecting piece is provided on each of the two reciprocating lines. It may be provided. Thereby, it is possible to appropriately detect the tension of the flexible member when the distal end working unit moves in any direction.

  Based on a signal supplied from the strain sensor, the tension of the flexible member is obtained, a predetermined alarm is generated when the tension exceeds a predetermined threshold, or the tension does not exceed the predetermined threshold. You may have a control part which adjusts the driving force of a motor. Thereby, it is possible to prevent excessive tension from being applied to the flexible member.

  It may have a control part which calculates | requires the tension | tensile_strength of the said flexible member based on the signal supplied from the said strain sensor, and generates a predetermined | prescribed alarm when the said tension | tensile_strength falls below a predetermined threshold value.

  The flexible member may be a wire.

  The experimental apparatus according to the present invention includes a base end rotating body connected to a rotating shaft of a motor, a tip end rotating body provided at a position away from the actuator unit, the base end rotating body, and the tip end rotating body. A reciprocating two-wire flexible member wound around, a tension detecting piece provided in the middle of the reciprocating two wires of the flexible member and provided with a strain sensor, the base end rotating body, and the A distance adjusting unit that adjusts a relative distance to the distal end rotating body; and a load sensor that is provided in the distance adjusting unit and detects a force applied between the proximal end rotating body and the distal end rotating body. Features.

  According to such a configuration, it is possible to check the operation of the flexible member by adjusting the tension on the flexible member. The tension detection piece is properly inserted in the middle of the flexible member, and the tension can be detected with little influence on the operation of the flexible member.

  In the medical manipulator and the experimental apparatus according to the present invention, by providing the tension detection piece, the tension of the flexible member in the working part can be detected easily and appropriately.

  Embodiments of a medical manipulator and an experimental apparatus according to the present invention will be described below with reference to FIGS.

  As shown in FIGS. 1, 2, and 3, the medical manipulator 10 according to the present embodiment is for performing a predetermined treatment by holding a part of a living body or a curved needle or the like on the distal end working unit 12. Usually, it is also called a grasping forceps or a needle driver (needle holder).

  The medical manipulator 10 includes an operation unit 14 that is manually held and operated, and a work unit 16 that is detachable from the operation unit 14, and a controller that is detachable from the operation unit 14 via a connector 24. A manipulator system having a (control unit) 27 is configured.

  The medical manipulator 10 has an operation unit 14 and a working unit 16 as a basic configuration. A controller 27 controls the medical manipulator 10 electrically, and extends from the lower end of the grip handle 26. The existing cable 62 is connected via the connector 24. For example, part or all of the functions of the controller 27 serving as the control unit can be integrally mounted on the operation unit 14.

  In the following description, the width direction in FIG. 1 is defined as the X direction, the height direction is defined as the Y direction, and the extending direction of the connecting shaft 48 is defined as the Z direction. Further, the right side is defined as the X1 direction, the left side as the X2 direction, the upward direction as the Y1 direction, the downward direction as the Y2 direction, the forward direction as the Z1 direction, and the backward direction as the Z2 direction. Further, unless otherwise specified, the description of these directions is based on the case where the medical manipulator 10 is in the reference posture (neutral posture). These directions are for convenience of explanation, and it is needless to say that the medical manipulator 10 can be used in any orientation (for example, upside down).

  The working unit 16 connects the tip operating unit 12 that performs the work, the connection unit 15 connected to the actuator block (actuator unit) 30 of the operation unit 14, and the tip operating unit 12 and the connection unit 15. A long and hollow connecting shaft 48. The working unit 16 can be detached from the operation unit 14 by a predetermined operation in the actuator block 30 and can perform cleaning, sterilization, maintenance, and the like.

  The distal end working unit 12 and the connecting shaft 48 are configured to have a small diameter, and can be inserted into a body cavity 22 from a cylindrical trocar 20 provided in a patient's abdomen or the like. Various procedures such as excision of the affected area, grasping, suturing and ligation can be performed.

  Next, the operation unit 14 will be described in detail.

  The operation unit 14 includes a grip handle 26 that is gripped by a human hand, a bridge 28 that extends from the top of the grip handle 26, and an actuator block 30 that is connected to the tip of the bridge 28.

  The connecting portion 15 includes an engagement piece 200 on the left and right side surfaces, and three fitting holes 202a, 202b, and 202c that open on the upper and lower surfaces. The three fitting holes 202a to 202c are provided in the vicinity of the ends in the Z1 direction and the Z2 direction, and extend in the Y direction.

  In the actuator block 30, motors (DC motors) 40 a, 40 b, and 40 c are provided in parallel along the Z direction so as to correspond to the three-degree-of-freedom mechanism of the distal end working unit 12. These motors 40 a to 40 c rotate under the action of the controller 27 based on the operation of the operation unit 14. The motors 40a to 40c are small and have a small diameter, and the actuator block 30 is configured in a compact flat shape. The motors 40a to 40c incorporate speed reducers 42a, 42b and 42c. The reduction gears 42a to 42c are, for example, planetary types, and the reduction ratio is about 1: 100 to 1: 300.

  The actuator block 30 is provided below the end of the operation unit 14 in the Z1 direction. Here, the actuator block 30 means a place where the working unit 16 is mounted, and is not limited to a place where the motors 40a to 40c are stored, but includes a connection surface 30a (see FIG. 3) with the bridge 28.

  The motors 40 a to 40 c are provided with rotary encoders 44 a, 44 b and 44 c that can detect the rotation angle, and the detected angle signals are supplied to the controller 27.

  As shown in FIGS. 2 and 3, the grip handle 26 extends from the end of the bridge 28 in the Y2 direction and has a length suitable for being gripped by a hand. Is provided with input means for the operation of the distal end working unit 12. That is, as such an input means, the trigger lever 32 and the switch 36 are provided in the Z1 direction close to the grip handle 26, and the composite input unit 34 and the operation switch 35 are provided in the Y1 direction.

  An LED 29 is provided at an easily visible position on the upper surface of the bridge 28 in the Z1 direction of the operation switch 35. The LED 29 is an indicator that indicates the control state of the medical manipulator 10, is a size that can be easily recognized by an operator, and is sufficiently small and light to such an extent that the operation is not hindered.

  A cable 62 connected to the controller 27 is provided at the lower end of the grip handle 26. The grip handle 26 and the cable 62 may be connected by a connector.

  The operation switch 35 is an input means for setting whether the operation state of the medical manipulator 10 is valid or invalid. The LED 29 is an indicator that indicates the control state of the medical manipulator 10, is a size that can be easily recognized by an operator, and is sufficiently small and light to such an extent that the operation is not hindered. The LED 29 is provided at a position with good visibility at a substantially central portion on the upper surface of the bridge 28. Since the LED 29 is arranged side by side with the operation switch 35, for example, the LED 29 is lit in synchronization with an ON operation by the operation switch 35. Thus, the operator can reliably recognize the input state by the LED 29 while operating the operation switch 35.

  In this case, the controller 27 reads the state of the operation switch 35, sets the operation mode when it is in the on state, and sets the motors 40a to 40c to a predetermined origin as an automatic home position return operation when switching from the on state to the off state. Return to the home position after returning to the origin. The operation mode is a mode in which the operation commands of the operation unit 14 are validated to drive the motors 40a to 40c. The stop mode is a mode in which the motors 40a to 40c are stopped regardless of the presence or absence of an operation command from the operation unit 14. These modes and operations are distinguished and controlled by the controller 27, and the lighting state of the LED 29 is switched.

  That is, the LED 29 is lit in green in the operation mode, lit in red in the stop mode, and flashes red in the automatic origin return mode in which the operation mode is changed to the stop mode.

  The composite input unit 34 is a composite input unit that gives rotation commands in the roll direction (axial rotation direction) and yaw direction (left-right direction) to the distal end working unit 12, and is, for example, a first input unit that operates in axial rotation. The roll direction can be instructed by using the second input means operating in the lateral direction. The trigger lever 32 is an input means for giving an open / close command to the gripper 60 (see FIGS. 1 and 5) of the distal end working unit 12.

  The composite input unit 34 and the trigger lever 32 are provided with input sensors 39a, 39b, and 39c for detecting operation amounts, respectively, and supply the detected operation signals to the controller 27.

  The trigger lever 32 is a lever that slightly protrudes in the Z1 direction slightly below the bridge 28, and is provided at a position where the operation with the index finger is easy.

  The trigger lever 32 is connected to the grip handle 26 by an arm 98 and is configured to advance and retreat with respect to the grip handle 26. The arm 98 is connected to the input sensor 39 c in the grip handle 26, and the advance / retreat amount of the trigger lever 32 is measured by the input sensor 39 c and supplied to the controller 27. The trigger lever 32 is configured to be able to perform an operation of applying a finger and pulling in the direction of the grip handle 26 (that is, the Z2 direction) and an operation of pushing out from the grip handle 26 in the Z1 direction. An open / close command can be given.

  Note that the switch 36 provided in the Y2 direction of the trigger lever 32 is an alternate type, and the gripper 60 is opened or closed by the trigger lever 32 by operating the switch 36, for example, a closed state. Can be held.

  On the upper surface 30b of the actuator block 30 on which the connecting portion 15 is placed, working portion detecting means 107 for detecting the presence or absence of the connecting portion 15 is provided in the vicinity of the end in the Z2 direction. The working unit detection means 107 is configured as a photo interrupter composed of an LED 107a that is a projector and a photodiode 107b that is a light receiver provided at opposite positions, and is connected between the LED 107a and the photodiode 107b. When the light shielding piece 109 (see FIG. 2) at the rear end of the portion 15 is inserted and shielded from light, it can be detected that the connecting portion 15 is mounted. The LED 107a and the photodiode 107b are provided in positions close to each other in the direction facing the X direction.

  The upper surface 30b is further provided with a connector 111 connected to the controller 27 and oriented in the Y1 direction.

  The actuator block 30 further includes two independent engaging portions 210 that hold the connecting portion 15 of the working portion 16, and three alignment pins 212 a, 212 b, and 212 c that have a positioning function and a holding mechanism for the connecting portion 15. Is provided.

  The two engaging portions 210 are provided at symmetrical positions on the left and right side surfaces (X1 and X2 side surfaces) of the actuator block 30, and have an operation surface 204 and a lever 206 extending from the operation surface 204 in the Y1 direction. . The lever 206 slightly protrudes in the Y1 direction from the upper surface of the actuator block 30, and the inside of the tip is tapered. The engaging portion 210 is elastically biased in the direction in which the lever 206 is directed inward by an elastic member (not shown).

  Two alignment pins 212a to 212c are provided near the end in the Z1 direction on the upper surface of the actuator block 30 and one near the end in the Z2 direction at positions facing the fitting holes 202a to 202c, and extend in the Y1 direction. Exist. Two alignment pins 212a and 212b are provided side by side in the X direction in the vicinity of the end in the Z1 direction.

  Thus, since the three alignment pins 212a to 212c are provided, the connecting portion 15 is supported at three points, and positioning can be performed easily and reliably. In addition, since the three alignment pins 212a to 212c are not linearly arranged, the connection portion 15 can be stably held against twisting in any direction. If two or more of the alignment pins 212a to 212c are provided, the connecting portion 15 is reliably positioned and stably held. In this case, it is more stable if two separated in the Z direction are selected.

  When removing the connection portion 15 from the operation portion 14, the levers 206 provided on both side surfaces of the actuator block 30 are pushed and tilted so as to open outward, and the wedge portion 206 a of the lever 206 is moved to the connection portion 15. It releases from the engagement piece 200 provided in the both sides | surfaces. As a result, the connecting portion 15 can be pulled upward (Y1 direction) from the operation portion 14 and can be removed. When the three alignment pins 212 on the upper surface 30 b of the actuator block 30 are fitted into the fitting holes 202 provided in the pulley housing 300, the connection portion 15 can be stably held.

  When attaching the connection portion 15 to the operation portion 14, the three alignment pins 212 are fitted into the fitting holes 202, respectively, and the connection portion 15 is pushed down (Y2 direction). As a result, the lever 206 once expands outward and then returns to its original position to engage with the engaging piece 200 and the connection is completed.

  On the connection surface 30 a of the operation unit 14, the camera 106 that reads the QR code of the ID unit 104 (see FIG. 4) of the connected work unit 16 and supplies the QR code to the controller 27, and the ID unit 104 of the connected work unit 16. Two LEDs 105 are provided for illuminating. The camera 106 is attached at a position facing the ID unit 104 of the working unit 16, and LEDs 105 are provided on the left and right of the camera 106. Here, as a reader of the ID (identification code) of the ID unit 104, a barcode reader or a barcode scanner can be used instead of the camera 106.

  The operation unit 14 is provided with many electrical components, and is expensive compared to the working unit 16 but has a long life.

  Next, the working unit 16 will be described in detail. The working unit 16 can be removed and cleaned from the operation unit 14 after the procedure is completed, and furthermore, only the working unit 16 can be periodically replaced with a new one to ensure sufficient reliability. . The working unit 16 is inexpensive because it does not have weak electrical components, and the distal end working unit 12 operates in the body cavity 22 and receives a load. Therefore, the working unit 16 is moderate in consideration of mechanical life, damage caused by washing of steam and heat, and the like. It is supposed to be replaced with a new one at the time. In consideration of the overall life span, the manufacturer sets a limit on the number of times the working unit 16 can be used, and the medical worker counts and manages the number of times the working unit 16 is used. Then, the working unit 16 disposes based on a prescribed procedure.

  As shown in FIGS. 1, 2, and 4, the connection portion 15 of the working portion 16 is covered with a resin cover 37 and is connected to the drive shafts of the motors 40 a to 40 c to be driven and rotated. Each of 50b and 50c is rotatably held. The pulleys 50 a to 50 c are stored in the pulley storage body 300.

  Wires 54 a, 54 b and 54 c (see FIGS. 5, 6, and 7) are wound around the pulleys 50 a to 50 c and extend through the hollow portion of the connecting shaft 48 to the distal end working unit 12. . The wires 54a to 54c are partially fixed so as not to slip with respect to the pulleys 50a to 50c (and 57a to 57c). The wires 54a to 54c can be of the same type and the same diameter.

  Cross-shaped coupling convex portions 51a, 51b and 51c are respectively provided at the lower ends in the Y2 direction of the pulleys 50a to 50c constituting the connecting portion 15, and the rotation shafts of the motors 40a to 40c constituting the actuator block 30 are cross-shaped. Coupling recesses 41a, 41b and 41c are provided. The coupling convex portions 51a to 51c and the coupling concave portions 41a to 41c can be engaged with each other. That is, in a state where the connection portion 15 is mounted on the actuator block 30, the rotation of the motors 40a to 40c is relative to the pulleys 50a to 50c. Is transmitted reliably. These engaging portions are not limited to a cross shape.

  As shown in FIG. 4, in the vicinity of the rear end of the connection unit 15, an ID unit 104 with an ID (identification code) that can identify the working unit 16 is provided.

  A QR code, which is a different two-dimensional bar code, is attached to the ID unit 104 so that each work unit 16 can be identified. The QR code of the ID unit 104 includes various types of information such as a manufacturing location, a manufacturing date, and a product name in addition to the model, specification, and serial number corresponding to each of the working units 16.

  A connector 113 that is connected to strain gauges 404a and 404b, which will be described later, and that faces the Y2 direction is provided at the lower side of the side surface of the pulley housing 300. The connector 113 and the connector 111 can be fitted to each other by the mounting operation of the connecting portion 15 to the actuator block 30, and the signals of the strain gauges 404 a and 404 b can be transmitted to the controller 27. The operator does not need to be particularly aware of the connectors 111 and 113 or perform a special operation when attaching or detaching the connecting portion 15.

  As shown in FIG. 5, the wires 54a, 54b, and 54c inserted through the connecting shaft 48 are respectively wound around corresponding pulleys (tip rotating bodies) 57a, 57b, and 57c of the distal end working unit 12 including the gripper 60. ing.

  Accordingly, when the pulley 50a is rotationally driven by the motor 40a with the wire 54a wound between the pulley 50a and the pulley 57a, the rotational driving force is transmitted to the pulley 57a via the wire 54a, The pulley 57a is rotated. Then, the rotation of the pulley 57a is sequentially transmitted to, for example, a gear, and the gripper 60 can be opened and closed.

  As shown in FIG. 6, the power transmission member including pulleys 50a to 50c, wires 54a to 54c, and pulleys 57a to 57c causes the distal end working unit 12 to move in the roll direction (Or axis rotation direction) and the yaw direction (Oy axis as a reference). Left and right direction) and a gripper opening and closing (opening and closing with the Og axis as a reference). Since the three-degree-of-freedom mechanism has an operation mechanism interference, the motors 40a to 40c cooperate to compensate for the mechanism interference.

  The motors 40a to 40c are driven based on signals obtained from input sensors 39a, 39b, and 39c that detect the operation amounts of the composite input unit 34 and the trigger lever 32 under the action of the controller 27.

  The wires 54a to 54c are preliminarily adjusted and assembled so as to have an appropriate prescribed tension between the pulleys 50a to 50c and the pulleys 57a to 57c. Each of the wires 54 a to 54 c is provided so that two reciprocating wires in the connecting shaft 48 are substantially parallel.

  In addition, the tension detection piece 400 is interposed in the middle of the two reciprocating lines of the wires 54a to 54c (also referred to as the wire 55 in the description of the tension detection piece 400). That is, six tension detection pieces 400 are provided. The tension detection piece 400 is a small plate that is long and small in the extending direction (Z direction) of the connecting shaft 48, and is provided in the connecting shaft 48. In order to avoid mutual interference, for example, as shown in FIG. 1, the six tension detection pieces 400 may be divided into two sets of three sets and shifted in the Z direction.

  As described above, a part of the wires 54a to 54c is fixed so as not to slip with respect to the pulleys 50a to 50c and 57a to 57c. Tension is applied and the other tension is reduced. In the medical manipulator 10, since the tension detection pieces 400 are provided on the two reciprocating wires, the tension of the wire 55 can be appropriately detected when the axis of the distal end working unit 12 moves in any direction. Can do.

  As shown in FIG. 7, the tension detection piece 400 includes a central narrow width portion 402, strain gauges (strain sensors) 404 a and 404 b provided on the front and back surfaces of the narrow width portion 402, and both ends in the longitudinal direction. And a hook 406 for hooking the provided wire 55.

  The tension detection piece 400 is a sufficiently strong material such as a nickel-base alloy, stainless steel, or hardened steel, and is suitable for tension detection.

  The hook 406 is provided with C chamfering at the opening and the outer end, and the corner 406a in the hook-shaped recess and the winding surface 406b of the wire 55 are formed in an arc shape, so that the wire 55 can be prevented from being damaged. The corner 406a has a 90 ° concave arc shape that matches the corner shape, and the winding surface 406b has a 180 ° convex arc shape that is smoothly connected to the front surface and the back surface. The opening directions of the two hooks 406 are opposite (X1 direction and X2 direction), and the balance is good.

  The width W1 of the concave portion of the hook 406 is suitably narrow so that the wire 55 is not unnecessarily displaced, and is preferably set to 1.5 to 4 times the diameter of the wire 55, for example. The width W2 of the tension detection piece 400 and the hook 406 is reasonably wide so as to have sufficient strength, is reasonably narrow for placement in the connecting shaft 48, and is light in consideration of power transmission efficiency. For example, it may be set to 1.5 to 3 times the width W1. Similarly, the thickness U of the tension detection piece 400 may be set to 1.5 to 4 times the diameter of the wire 55, for example.

  When at least one of the thickness U and the width W3 in the narrow width portion 402 is set to be appropriately small, the stretch of the narrow width portion 402 becomes relatively large, and the strain of the strain gauges 404a and 404b becomes large, thereby improving measurement accuracy. .

  The strain gauges 404 a and 404 b are provided in a direction in which strain in the Z direction can be detected, and the signal line 408 is connected to the connector 113. Since the strain gauges 404a and 404b are respectively provided on the front and back of the tension detection piece 400, the influence of the tension detection caused by the bending of the tension detection piece 400 can be reduced. As is apparent from FIG. 7, the strain gauges 404a and 404b are arranged in a straight line connecting the wires 55 at both ends.

  The signals from the strain gauges 404a and 404b may be measured independently and then the influence of the bending of the tension detecting piece 400 may be corrected by calculation. Alternatively, the strain gauge 404a and the strain gauge 404b may be connected in series or in parallel, and may be measured as an apparently one sensor. As a result, fewer amplifiers are connected and the calculation process is simplified.

  The wire 55 has a ring 412 formed by folding the end portion 409 and crimping a sleeve-like fixture 410 to a predetermined position of the wire 55, and the ring 412 is hung on the hook 406. . The means for forming the ring 412 is not limited to the fixture 410 and may be welding, screwing, or the like. The shape of the front surface and the back surface of the hook 406 may be a cross-sectional shape corresponding to the ring 412. The wires 55 are respectively hung on the hooks 406 at both ends of the tension detecting piece 400 in the same manner.

  The controller 27 amplifies the signals supplied from the strain gauges 404a and 404b with a predetermined amplifier, performs a predetermined correction or the like to obtain the tension T of the wire 55, and issues an alarm (sound) when the tension T exceeds the threshold T1. , Sound, lamp, etc.) or the driving force of the motors 40a to 40c is adjusted so that the tension T does not exceed the threshold value T1. Thereby, it is possible to prevent the tension 55 from being excessively applied to the wire 55.

  Further, the controller 27 obtains the tension of the wire 55 based on the signals supplied from the strain gauges 404a and 404b, and generates an alarm when the tension T falls below the threshold value T2. This is because it is considered that some abnormality has occurred in the wire 55. However, of the two reciprocating wires 55 of the wire 55, it is allowed that the tension T falls below the threshold value T2 on the side where the tension is lowered according to the operation state, and no alarm is generated. The threshold value T2 may be set to a value that is slightly smaller than the initial prescribed tension that is adjusted and applied in advance to the wires 54a to 54c during assembly.

  Next, a procedure for detecting the tension T of the wire 55 and performing a corresponding process with the medical manipulator 10 configured as described above will be described. In the following description, one of the two reciprocating wires 55 of the wire 55 is distinguished as Ta, and the other as Tb (see FIG. 6). Since the wires 54a to 54b are basically processed in the same manner, the wire 54a will be described as a representative wire 55.

  First, in step S1 of FIG. 8, the signals after amplification of the strain gauges 404a and 404b provided on the front and back of the tension detection piece 400 are corrected (for example, averaged) by a predetermined method to obtain the tensions Ta and Tb. As described above, the two strain gauges 404a and 404b may be connected in series or in parallel.

  In step S2, the tensions Ta and Tb are compared with the threshold value T1, and if Ta> T1 or Tb> T1, the process proceeds to step S3. Otherwise, the process proceeds to step S5.

  In step S3, since the tension Ta or the tension Tb is excessive, an alarm is generated. Through this step S3, the operator can recognize that the wire 55 is excessively tensioned and can reduce the tension by a predetermined operation.

  In step S4, the driving torque of any one of the corresponding motors 40a to 40c is appropriately reduced. This can be achieved by lowering the target position when position control is being performed, and lowering the target torque when torque control is being performed. Thereafter, the procedure returns to step S1 and the procedure is repeated. By repeating this step S4, the driving force of the motors 40a to 40c is adjusted so that the tension does not exceed the threshold value T1, and it is possible to prevent the wire 55 from being excessively tensioned. Either step S3 or step S4 may be omitted depending on the design conditions.

  In step S5, the operation status at that time is recognized, it is determined which of the two reciprocating wires 55 the tension increases, and if the tension Ta increases, the process proceeds to step S6, where the tension Tb increases. If so, the process proceeds to step S7.

  In step S6, the tension Ta is compared with the threshold value T2, and if Ta <T2, the process proceeds to step S8, and otherwise, the process returns to step S1.

  In step S7, the tension Tb is compared with the threshold value T2. If Tb <T2, the process proceeds to step S8, and otherwise, the process returns to step S1.

  In step S8, an alarm is generated because the tension of the wire 55 is too small.

  As described above, according to the medical manipulator 10 according to the present embodiment, by providing the tension detection piece 400 in the middle of the wire 55, the tension T of the wire 55 in the working unit 16 can be detected easily and appropriately. Can do.

  In particular, in the medical manipulator 10, the working unit 16 can be attached to and detached from the operation unit 14, the required life of the working unit 16 is relatively short, and the wires 54 a to 54 c have a relatively low life specification. Therefore, it is preferable that the tension detection piece 400 can detect the tension T and perform appropriate handling processing.

  The tension detection piece 400 is a plate that is long in the Z direction, does not hinder the operation of the wire 55, has an appropriate rigidity, and is easily provided with strain gauges 404a and 404b, and accurately detects the tension T. can do.

  Such a tension detection piece 400 of the medical manipulator 10 is preferably used for inspecting the tension T of the wire 55 according to the operation state not only at the product level but also at the product development stage. Thus, by properly detecting the tension T of the wire 55 in the product development stage, the necessary and sufficient strength of the wire 55 can be set appropriately. Thus, in the medical manipulator 10 manufactured by selecting the wire 55 having an appropriate strength at the product development stage, the tension detecting piece 400 and its peripheral system may be omitted at the product level.

  The above embodiment may be applied to a medical robot system 800 as shown in FIG. 9, for example.

  The medical robot system 800 includes an articulated robot arm 802 and a console 804, and the working unit 806 is connected to the tip of the robot arm 802. A manipulator 808 having a mechanism similar to that of the medical manipulator 10 is provided at the tip of the robot arm 802. The robot arm 802 may be any means that moves the working unit 806, and is not limited to a stationary type, but may be an autonomous moving type, for example. The console 804 may take a configuration such as a table type or a control panel type.

  If the robot arm 802 has six or more independent joints (such as a rotation axis and a slide axis), the position and orientation of the working unit 806 can be arbitrarily set. The manipulator 808 at the tip is integrated with the tip 810 of the robot arm 802. Instead of the actuator block 30 (see FIG. 1), the manipulator 808 has an actuator block 812 having a proximal end connected to the distal end portion 810 and accommodating a motor therein.

  The robot arm 802 may operate under the action of the console 804, and may be configured to perform an automatic operation by a program, an operation following a joystick 814 provided on the console 804, and a composite operation thereof. The console 804 includes the function of the controller 27 (see FIG. 1). The working unit 806 is provided with the distal end working unit 12.

  The console 804 is provided with two joysticks 814 as operation command units and a monitor 816. Although not shown, two robot arms 802 can be individually operated by two joysticks 814. The two joysticks 814 are provided at positions that can be easily operated with both hands. On the monitor 816, information such as an image by an endoscope is displayed.

  The joystick 814 can move up and down, move left and right, twist, and tilt, and can move the robot arm 802 in accordance with these operations. The joystick 814 may be a master arm. The communication means between the robot arm 802 and the console 804 may be wired, wireless, network, or a combination thereof.

  Next, the experimental apparatus 900 used in the development stage of the medical manipulator 10 will be described. The experimental apparatus 900 is an experimental apparatus for selecting the wires 54a to 54c of the medical manipulator 10 and examining appropriate tensions thereof. Constituent elements of the experimental apparatus 900 that are the same as those of the medical manipulator 10 are assigned the same reference numerals, and detailed descriptions thereof are omitted.

  The experimental apparatus 900 is fixed to a predetermined bench, and is separated from the motors 40a to 40c, pulleys 50a to 50c as base end rotating bodies connected to the rotation shafts of the motors 40a to 40c, and the actuator block 30. Pulleys 57a to 57c as three tip rotating bodies arranged in parallel to each other, two-way reciprocating wires 54a to 54c wound around the pulleys 50a to 50c and the pulleys 57a to 57c tip rotating bodies, and the wires 54a to 54c. 54c, and six tension detecting pieces 400 provided with strain gauges 404a and 404b (see FIG. 7). The signal lines of the strain gauges 404a and 404b provided on the front and back sides of the tension detection piece 400 are connected to an amplifier 902, which can amplify the strain and measure the tensions Ta and Tb. The motors 40 a to 40 c are driven by the controller 27 in the same situation as the actual procedure as with the medical manipulator 10 described above.

  The experimental apparatus 900 is further provided in distance adjustment units 904a to 904c and distance adjustment units 904a to 904c that individually adjust relative distances in the Z direction between the pulleys 50a to 50c and the pulleys 57a to 57c, and the pulleys 50a to 50c. Load sensors 906a to 906c for detecting forces Fa, Fb and Fc applied between the pulleys 57a to 57c. The relative distance between the pulleys 50a to 50c and the pulleys 57a to 57c is measured by a distance detector (not shown).

  The distance adjusting unit 904a includes an L-shaped mounting unit 908a that mounts the motor 40a, the encoder 44a, the speed reducer 42a, and the pulley 50a coaxially in an integrated configuration, and a moving piece 912 that moves in the Z direction by operating the dial 910. And a rail 914 that slidably holds the mount 908 and the movable piece 912. One side of the mount portion 908a holds the motor 40a, the encoder 44a, the speed reducer 42a, and the pulley 50a and extends in the Y1 direction, and the other side extends in the Z1 direction. The end of the mount portion 908a and the moving piece 912 are connected by a load sensor 906a, so that the force Fa can be detected. When the dial 910 is rotated, the protruding amount of the rod 915 from the base block 916 is adjusted, and the moving piece 912 connected to the end of the rod 915 is displaced in the Z direction.

  The mount portions 908a, 908b and 908c corresponding to the pulleys 50a, 50b and 50c have different L-shaped sizes so as not to interfere with each other. Other than that, the distance adjustment units 904b and 904c have the same configuration as the distance adjustment unit 904a, and thus detailed description thereof is omitted.

  According to the experimental apparatus 900 having such a configuration, it is possible to check the operation of the wires 54a to 54c by adjusting the forces Fa, Fb and Fc as the total tension on the wires 54a to 54c. The tension detection piece 400 is properly inserted in the middle of the wires 54a to 54c, and can easily detect the tensions Ta and Tb with little influence on the operation of the wires 54a to 54c. The tension | tensile_strength of the wires 54a-54c according to a condition can be test | inspected.

  In the medical manipulator 10 (see FIG. 1) in which the tension is appropriately set by the experimental apparatus 900, the tension detection piece 400 may be omitted.

  The medical manipulator and the experimental device according to the present invention are not limited to the above-described embodiments, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

It is a perspective view of the medical manipulator concerning this embodiment. It is a side view of the medical manipulator which isolate | separated the working part and the operation part. It is a perspective view of an operation part. It is a partial cross section perspective view of a connection part. It is a perspective view of a front-end | tip operation | movement part. It is a schematic diagram which shows the basic composition of a pulley, a wire, and a front-end | tip operation | movement part. It is a perspective view of a tension detection piece. It is a flowchart of the procedure which detects the tension | tensile_strength of a wire with a medical manipulator and performs a corresponding | compatible process. It is a perspective view of the medical robot system which connected the medical manipulator to the front-end | tip of a robot arm. It is a top view of the experimental apparatus which concerns on this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Medical manipulator 12 ... Tip operation | movement part 14 ... Operation part 15 ... Connection part 16,806 ... Working part 27 ... Controller (control part)
30, 812 ... Actuator block (actuator part)
40a-40c ... motor 48 ... connecting shafts 50a-50c, 57a-57c ... pulleys 54a-54c, 55 ... wires 111, 113 ... connectors 400 ... tension detection pieces 404a, 404b ... strain gauges (strain sensors) 406 ... hooks 410 ... Fixing device 412 ... Wheel 800 ... Medical robot system 900 ... Experimental apparatus

Claims (10)

An actuator unit equipped with a motor;
A connecting portion comprising a rotating body that is detachably attached to the actuator portion and connected to a rotating shaft of the motor;
A tip operating portion provided at a tip of a connecting shaft extending from the connecting portion and interlocking with the rotating body via a flexible member;
A tension detecting piece interposed in the middle of the flexible member and provided with a strain sensor;
A medical manipulator characterized by comprising: The medical manipulator according to claim 1, wherein
The medical manipulator, wherein the tension detection piece is a plate body that is long in the extending direction of the connecting shaft. The medical manipulator according to claim 2,
The medical manipulator, wherein the strain sensor is provided on each of the front and back sides of the tension detection piece. The medical manipulator according to claim 2 or 3,
The tension detection piece includes a hook for hooking the flexible member on both ends in the longitudinal direction. The medical manipulator according to any one of claims 2 to 4,
The medical manipulator, wherein the tension detecting piece is a nickel-based alloy, stainless steel, or hardened steel. In the medical manipulator according to any one of claims 1 to 5,
The flexible member is wound around the distal end rotating body of the distal end working unit, and two reciprocating lines in the connecting shaft are provided substantially in parallel,
The medical manipulator, wherein the tension detecting pieces are provided on two reciprocating wires. The medical manipulator according to any one of claims 1 to 6,
Based on a signal supplied from the strain sensor, the tension of the flexible member is obtained, a predetermined alarm is generated when the tension exceeds a predetermined threshold, or the tension does not exceed the predetermined threshold. A medical manipulator having a control unit for adjusting a driving force of a motor. In the medical manipulator according to any one of claims 1 to 7,
A medical manipulator comprising a control unit that obtains a tension of the flexible member based on a signal supplied from the strain sensor and generates a predetermined alarm when the tension falls below a predetermined threshold. In the medical manipulator according to any one of claims 1 to 8,
The medical manipulator, wherein the flexible member is a wire. A proximal rotating body connected to the rotating shaft of the motor;
A tip rotating body provided at a position away from the actuator unit;
A reciprocating two-wire flexible member wound around the base end rotating body and the tip end rotating body;
A tension detecting piece provided in the middle of the reciprocating two wires of the flexible member and provided with a strain sensor;
A distance adjusting unit that adjusts a relative distance between the base end rotating body and the tip end rotating body;
A load sensor that is provided in the distance adjustment unit and detects a force applied between the base end rotating body and the tip end rotating body;
An experimental apparatus characterized by comprising:

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